PAUL D. GAMLIN - Primate Testing - 2006

Abstract: DESCRIPTION (provided by applicant):
Visual input to the suprachiasmatic nucleus (SCN) serves to entrain the
circadian pacemaker while input to the pretectal olivary nucleus (PON)
mediates the pupillary light reflex. In rodents, a population of
intrinsically photoreceptive retinal ganglion cells projects to the PON
and SCN, and are important to pupillary responses and entrainment of
circadian rhythms. There is now compelling evidence that similar
ganglion cells exist in primate retina, project to the ON and lateral
geniculate nucleus, and contribute significantly to pupillary responses.
The goals of the proposed studies in primates are therefore to: 1)
further characterize these intrinsically-photoreceptive ganglion cells;
2) investigate their influence on the visual physiology of PON neurons;
3) examine their hypothesized projections to the SCN; 4) determine their
influence on the visual physiology of SCN neurons; and 5) determine
their contribution to pupillary responses in the primate. These are
important research questions, since the circadian system regulates such
physiologically important behaviors as activity, body temperature, and
sleep/wake cycles, and the pupillary light reflex is a clinically
important diagnostic tool. These studies have important implications for
our understanding of the visual, circadian, and pupillary systems in
primates. If, as preliminary data indicates, pupillary responses are
influenced throughout much of the photopic range by inputs from
intrinsically photoreceptive ganglion cells, this has important
consequences for our understanding the pupillary light reflex and for
its clinical evaluation. Also, if the same retinal ganglion cells
project to both SCN and PON, then it will be possible to extrapolate
from information that is readily derived in the pupillary system to the
circadian system, where entrainment experiments take longer. Finally,
beside their roles in pupil control and circadian rhythms, these
ganglion cells project to the lateral geniculate nucleus and are likely
to have very broad-reaching effect on other human visual behaviors.

Vision Science Research Center, University of Alabama, Birmingham,
Alabama 35294

Submitted 16 December 2002; accepted in final form 7 January 2003

Preparation of animals
Five adult monkeys (Macaca mulatta; 4 male, one female, aged 3–8 yr)
were used in this study. All experimental procedures were approved by
the Institutional Animal Care and Use Committee and complied with the
U.S. Public Health Service Policy on Humane Care and Use of Laboratory
Animals. Surgical procedures that have been reported previously are only
briefly described (Gamlin et al. 1994 ). Animals underwent three sterile
surgical procedures under pentobarbital sodium anesthesia.
Postsurgically they received analgesics to minimize pain. Animals were
first implanted with a stainless steel head-holder in the first surgery.
Then, to measure eye position, 4–10 wk later a search coil was implanted
under the conjunctiva of one eye in the second surgery (Fuchs and
Robinson 1966 ; Judge et al. 1980 ). Once animals reached a satisfactory
level of training, a second eye coil was implanted on the other eye. In
this final surgery, two chambers, one on each side of the head, were
implanted stereotaxically over the pretectum at an 18o angle to the
sagittal plane over 15-mm holes trephined in the skull. Methods for
behavioral training, stimulus presentation, and eye movement recording
are described in the accompanying paper (Clarke et al. 2003 ).

Please email: PAUL D. GAMLIN,
pgamlin@uab.edu to protest the inhumane use of animals in this
experiment. We would also love to know about your efforts with this
cause:
saen@saenonline.org

Rats, mice, birds, amphibians and other animals have
been excluded from coverage by the Animal Welfare Act. Therefore research
facility reports do not include these animals. As a result of this
situation, a blank report, or one with few animals listed, does not mean
that a facility has not performed experiments on non-reportable animals. A
blank form does mean that the facility in question has not used covered
animals (primates, dogs, cats, rabbits, guinea pigs, hamsters, pigs,
sheep, goats, etc.). Rats and mice alone are believed to comprise over 90%
of the animals used in experimentation. Therefore the majority of animals
used at research facilities are not even counted.